Artigo
Índice de seleção bioeconômico para fêmeas de corte da raça nelore
Fecha
2012-12-01Registro en:
Archivos de Zootecnia, v. 61, n. 236, p. 537-548, 2012.
0004-0592
1885-4494
10.4321/S0004-05922012000400006
S0004-05922012000400006
2-s2.0-84871696330
S0004-05922012000400006.pdf
9096087557977610
Autor
Universidade Estadual Paulista (Unesp)
Gensys Consultores Associados S/S Ltda
Resumen
The reproductive efficiency of Nellore females was described on the basis of sexual precocity, staying productive in the herd (NP), maternal productivity (PM) and estimated cost for maintenance (CM). The combination of these traits resulted in the bioeconomic maternal revenue index (RMat) ensures reproductive efficiency. The index estimates the return in kilograms of live weight produced per cow per year. In addition, the composition of calf weight produced was considered, adding to the PM the information on the scores of conformation, muscling and early finishing at weaning, in order to input the calf biotype. The females considered precocious had their age at first calving before 30 months. The NP was expressed by the number of calving till 53 months of age. The CM was calculated according to the estimated feed intake of dry matter. The estimated average RMat was 62.02±24.12 kg/ cow/year. Estimates of additive genetic and residual variances for RMat, using restricted maximum likelihood under a single trait animal model was equal to 195.35 and 242.96, respectively. The heritability estimated was 0.45±0.02, indicating that RMat is inheritable and can be applied in the breeding program to improve reproductive efficiency. The NP was the main component of variation for RMat. Sires selected based on RMat tended to have more efficient daughters.